Arsenic is everywhere: cause for concern?

309 Pages·2016·4.58 MB·English

by  William R Cullen

Arsenic is Everywhere: Cause for Concern?
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Arsenic is Everywhere: Cause
for Concern?
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78 William R. Cullen
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78 University of British Columbia, Vancouver, Canada
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9/ Email: [email protected]
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or Kenneth J. Reimer
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s.rs Royal Military College of Canada, Kingston, Canada
ub Email: [email protected]
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s.r Print ISBN: 978-1-78262-314-4
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u PDF eISBN: 978-1-78262-663-3
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on A catalogue record for this book is available from the British Library
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2 © William R. Cullen and Kenneth J. Reimer 2017
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6 Apart from fair dealing for the purposes of research for non-commercial purposes or for
n 0 private study, criticism or review, as permitted under the Copyright, Designs and Patents
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ed Act 1988 and the Copyright and Related Rights Regulations 2003, this publication may
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blis not be reproduced, stored or transmitted, in any form or by any means, without the prior
u permission in writing of The Royal Society of Chemistry or the copyright owner, or in
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the case of reproduction in accordance with the terms of licences issued by the Copyright
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Published by The Royal Society of Chemistry,
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Printed in the United Kingdom by CPI Group (UK) Ltd, Croydon, CR0 4YY, UK
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66 Preface
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oi:1 In 2008, in his book Is Arsenic an Aphrodisiac? The Sociochemistry of an
g | d Element, Bill Cullen described the way in which arsenic and its compounds
or have become embedded in our social fabric, for good and for ill, thereby cre-
c.
s ating a unique interface between society and chemistry. That book covered
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b a wide range of topics, including arsenic’s use as a poison and as a medicine
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p:// from the time of the ancient Romans to the present day; its role in war; and
htt its supposed (now disproven) associations with the death of Napoleon and
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o sudden infant death syndrome. It also described how arsenic is all around
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01 us: in our soil, our water and the food we eat. It is at that point that we pick
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er up this story. This new book is not intended to be a second edition of the
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m first. Much has happened in the intervening years, and as arsenic is at least
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e as much on the public’s radar as it was before, we attempt to present this new
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6 information (and misinformation) in a form that is easily deciphered and
on 0 understood by the reader.
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he We believe that the very word “arsenic” triggers fear and anxiety in human
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bli society, such is the power of its historical associations with death. So it is
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there is arsenic in apple juice was, “I didn’t know that I was giving poison to
my child!” The reality is that arsenic, a naturally occurring element, is every-
where around us so it would be surprising (to chemists) to not find at least
some arsenic in everything we eat and drink.
We explore the topic of arsenic’s ubiquitousness in our environment
in Chapter 2 and also illustrate the harm that it can cause when naturally
present in high concentrations in drinking water. In Bangladesh and West
Bengal, India, naturally occurring arsenic in the water has impacted the lives
of millions of people; the situation has been called the “largest mass poi-
soning of a population in history.” Unfortunately, despite some mitigation
efforts, 52 million people in these regions are still drinking water containing
Arsenic is Everywhere: Cause for Concern?
By William R. Cullen and Kenneth J. Reimer
© William R. Cullen and Kenneth J. Reimer, 2017
Published by the Royal Society of Chemistry, www.rsc.org
v
View Online
vi Preface
arsenic above the commonly accepted limit of 10 ppb (with 20 million con-
suming concentrations of more than 50 ppb), and the impacts of this are
expected to be felt for generations to come. It may therefore come as a sur-
prise to many to learn in Chapter 3 that arsenic is involved in life processes
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0 and that at least one microbe requires arsenic for life. These processes have
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F been going on since the Earth’s beginnings, and through them, arsenic the
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3 element is transformed into many different arsenic compounds, each with
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2 its own distinct toxicity. One compound in particular, commonly found in
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8 marine organisms, is not toxic at all.
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8 In Chapter 4, we address the issue of the toxicity of arsenic, starting with
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9/ the most commonly held perception of arsenic as a poison, which, if given in
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10 sufficient amount and a specific form, can cause death fairly quickly. More
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1 complicated is determining the effects of day-to-day, “chronic” exposure to
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d arsenic in smaller amounts and in different chemical forms. While it is not
org | uncommon to hear it said that inorganic arsenic is the dangerous one and
sc. that organic arsenic is safe, the reality is not that simple. A great deal of sci-
bs.r entific effort has gone into trying to answer the question of whether there is
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p://p a “safe dose” of arsenic or whether any amount may cause us harm. The jury
htt is still out on the answer, although it does appear that some individuals may
on be more vulnerable to arsenic’s effects than others, especially in early life.
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1 Yet, as we explore in Chapters 5 and 6, there has been a long history of use
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er of arsenic in medicine and in alternative medicine, and it provides the most
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m effective cure for a certain form of leukemia, APL.
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ec Chapter 7 looks at our exposure to arsenic in our diet—yes, in our food.
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6 (Arsenic is everywhere, after all!) As mentioned earlier, we should expect to
n 0 find arsenic in our food because plants and animals take up arsenic from
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ed the natural environment. Research is being done around the globe to bet-
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bli ter understand the implications of daily dietary exposure to arsenic and the
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P risks it might, or might not, pose. Those who are fortunate enough to not
have arsenic-contaminated drinking water and who can afford a varied diet
can manage their arsenic exposure. To assist with that, in Chapter 8 we invite
you to dinner and offer some information about the servings of arsenic you
might be putting on your plate. Overall, our hope is to demystify arsenic and
to provide you with tools to deal with the real, rather than perceived, risks.
In Is Arsenic an Aphrodisiac? Bill Cullen described how he got into the
arsenic field, and we repeat some of that information here. In 1953, in his
second year at the University of Otago, Dunedin, New Zealand, he listened
to a lecture by Dr Ted Corbett about the organic chemistry of arsenic and
was hooked. Bill knew from a very early age that he was going to be a chem-
ist but not what sort, so this was a very significant event. In 1956 he went
to Cambridge, England, to study for a PhD with Professor HJ Emeleus, who
suggested the study of a new class of arsenic compounds that contained flu-
orocarbon groups. In 1958 Bill accepted a position at the University of British
Columbia, Canada, and began independent research that built on his PhD
thesis. Throughout the ensuing years, arsenic was never very far from his
thoughts.
View Online
Preface vii
Ken Reimer received his PhD from the University of Western Ontario,
Canada, in the field of organometallic chemistry, the interface between
inorganic and organic chemistry. He had always been interested in inter-
disciplinary science, and the role of metals in biological systems led him
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0 to postdoctoral work with Professor Brian James at the University of British
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F Columbia. It was there that he met Bill Cullen and learned about arsenic
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3 (a metalloid) through the many fascinating discussions of the Bioinorganic
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2 Chemistry Group. Ken began looking at arsenic when he started his first
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8 full-time academic job at Royal Roads Military College in British Columbia,
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8 Canada. The College had begun an oceanography program, and studying
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9/ arsenic in the sea and marine organisms was a natural choice for Ken. It also
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10 began a life-long involvement with field work. Later, as Ken moved to the
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1 Royal Military College of Canada in Kingston, Ontario, he became involved
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d in many applied projects, among them as the scientific authority for the
org | environmental remediation of the radar sites of the Distant Early Warning
sc. Line—one of Canada’s largest environmental cleanup projects. The problem
bs.r there was not arsenic but rather PCB contamination that affected the food
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p://p sources of local Inuit. It became important to understand the concerns of
htt the Inuit and to share knowledge about the problem and possible solutions.
on It was during this time that Ken became interested in risk communication,
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1 and some of his most memorable professional experiences have come from
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er meetings in small community halls in the Arctic. Arsenic was, however,
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m always part of Ken’s basic research program, and sharing and communicat-
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ec ing the realities of arsenic exposure to the public became a natural next step.
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6 We have tried to write this book so that the non-chemist can follow the
n 0 fascinating but complicated story of arsenic in our lives. We hope that the
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ed chemist will also find it instructive even though we have simplified the chem-
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bli istry. We will not try to thank all of the many colleagues who have enriched
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P our lives along the way for fear of inadvertently leaving someone out, but we
are eternally grateful to all of them. There are some individuals, however,
who made this book possible. Thanks to Dr Iris Koch, our former student,
colleague and friend, who reviewed the entire manuscript and provided help-
ful assistance and encouragement. To Dr Michelle Nearing, Ken’s colleague
and last PhD student before retirement, we offer our gratitude for help with
the figures. John Lawless was always willing to assist with our technical
issues—and there were many—thanks John. Susie Rance, our tireless editor,
kept us focused on making the book grammatically correct, interesting and
accessible to the general audience (somehow “track changes” will never look
the same again). We thank Deborah Reimer for her constant support and
encouragement and for giving up so much golf time to incorporate all of the
references. Ken offers a special thanks to Sapphire and Mya, who reminded
him that one should take time from writing to pet the cats.
Bill Cullen
Ken Reimer
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66 Abbreviations
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oi:10. AADLAI RA a acs cleopwt aabs lree daasoilny ainbltya ke BMDL05 dreosspeo ants we hisi clhik tehlye t o be
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g | achievable smaller than 5%
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c. AMA Australian Medical bw body weight
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s.r Association CAM complementary and
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pu APL acute promyelocytic alternative medicine
p:// leukemia CFS Center for Food Safety
n htt As3MT arsenic methyltransferase CSF cancer slope factor
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16 As(iii) arsenite (H3AsO3) DMA(v) dimethylarsinic acid
0 As(v) arsenate (H AsO ) DOC dissolved organic
2 3 4
er As O arsenolite, white oxide (white carbon
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e arsenic) DPHE Department of Public
c
De As2S3 yellow sulfide, orpiment Health Engineering
n 06 As4S4 realgar (red arsenic) (Government of
o AsB arsenobetaine Bangladesh)
d
she AsH3 arsine DSHEA Dietary Supplement Health
bli AsLp arsenolipid and Education Act
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ATSDR US Agency for Toxic EDI estimated daily intake
Substances and Disease EFSA European Food Safety
Registry Authority
AYUSH (Indian) Department of ESPHGAN European Society for
Ayurveda, Yoga and Natu- Paediatric Gastroenter-
ropathy, Unani, Siddha and ology Hepatology and
Homeopathy Nutrition
BMD benchmark dose EU European Union
BMDL lowest dose that might FAO Food and Agriculture
give the particular Organization of the United
response Nations
Arsenic is Everywhere: Cause for Concern?
By William R. Cullen and Kenneth J. Reimer
© William R. Cullen and Kenneth J. Reimer, 2017
Published by the Royal Society of Chemistry, www.rsc.org
xi
View Online
xii Abbreviations
FDA US Food and Drug MMA(v) monomethylarsonic
Administration acid
FSA Food Standards Agency MOA mode of action
(UK) NASA National Aeronautics and
11 FSANZ Food Standards Space Administration
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P Australia New Zealand NCCIH US National Center for
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3- HPLC-ICP MS high-performance Complementary and
3
6
6 liquid chromatography Integrative Health
2
6
2 coupled to an induc- NCCN National Comprehensive
8
7
1 tively coupled mass Cancer Network
8
97 spectrometer ng nanogram
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3 HQ hazard quotient NGO non-governmental
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0. HRW Human Rights organization
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oi: Watch NHP natural health product
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g | IARC International Agency NOAA (US) National Oceanic
or for Research on and Atmospheric
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s.rs Cancer Administration
ub iAs inorganic arsenic NOAEL no observed adverse effects
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p:// IATP Institute for level
htt Agriculture and NRC (US) National Research
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o Trade Policy Council
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1 ICDDR,B International Centre NTNC non-transient,
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er for Diarrhoeal non-community
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m Disease Research, OBRS organic brown rice syrup
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ec Bangladesh ORV off-road vehicle
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6 IRIS Integrated Risk Infor- PM particulate matter
n 0 mation System ppm parts per million
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ed JECFA Joint FAO/WHO Expert PWTI provisional tolerable weekly
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blis Committee on Food intake
u Additives RfD reference dose
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LD lethal dose, 50% ROS reactive oxygen species
50
(amount of a chemical, SAM S-adenosylmethionine
given all at once, that SNFA Swedish National Food
causes the death of Agency
50% of a group of test T&CM traditional and
animals in a relatively complementary medicine
short time tAs total arsenic
LOAEL lowest observed TCLP toxicity characteristic
adverse effect level leaching procedure
M metre TCM traditional Chinese
MCL maximum medicine
contaminant level TDI tolerable daily intake
MCLGs maximum contaminant TETRA tetramethylarsonium ion
level goals TMA trimethylarsine
mg kg−1 d−1 milligrams per TMAO trimethylarsine oxide,
kilogram of body (CH ) AsO
33
weight per day UK United Kingdom